P007

Comparative characterization of human umbilical cord blood and adipose tissue–derived multipotent mesenchymal stem cells

Kamalaveni R. Prabakar, Muhil Prabakar, Jorge Montelongo, Armando Mendez, Camillo Ricordi, Luca Inverardi

Diabetes Research Institute, University of Miami, Miami, FL, United States

Cell-based therapies will benefit from the definition of appropriate sources of pluripotent adult stem cells. The mesenchymal stroma harbors a population of cells that can self-renew and differentiate into multiple lineages.The bone marrow contains mesenchymal stromal cells (AKA mesenchymal stem cells, MSCs),which have potential to differentiate intofat, bone and cartilage, and could therefore represent a good source of MSC. However, autologous bone marrow procurement has potential limitations and therefore alternative, less invasive sources of MSCs are highly desirable. The umbilical cord-blood and adipose tissue have been suggested as viable options.The aim of this study was to compare selected biological characteristics of MSCs derived from cord blood (CB-MSCs) and adipose tissue (AT-MSCs).Cells were analyzed for proliferation, surface marker expression, stem cell gene expression and multi-lineage plasticity.MSCs derived both from CB and AT were similar in morphology and antigenic phenotype; however, the proliferation potential and yield were superior in CB-MSCs than in AT-MSCs. Also, there were significant differences in proliferation, population doubling time and senescence associated with the age of the donor of AT-MSCs; younger donors’ cells showed better proliferation and less senescence. The adipogenic, osteogenic and chondrogenic differentiation potential was not grossly different between studied populations (CB-MSCs vs. AT-MSCs). MSCs from both sources expressedthe pluripotent stage–specific nuclear transcription factorOCT4 and surface stemness markers SSEA-3 and SSEA-4. However, the frequency of MSCs expressing these stem cell genes was higher in CB-MSCs than in AT-MSCs (OCT4: 80-90% for CB-MSCs and 15-30% for AT-MSCs; SSEA3 and SSEA4: 15-30% for CB-MSCs and 3-15% for AT-MSCs). The features seen in the MSCs derived from the umbilical cord may reflecttheir early developmental stage in ontogenesis. Further refinement of the characterization and functional studies are necessary to consider these MSCs for use in regenerative medicine.